Should I have bet this turn?

[stabn]

First hand at the table with no reads as a mid position poster.

Party Poker 0.5/1 Hold'em (8 handed) converter

Preflop: Hero is MP1 with T[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/spade.gif[/img]. Hero posts a blind of $0.5.
UTG calls, UTG+1 calls, <font color="#CC3333">Hero (poster) raises</font>, MP2 folds, CO calls, Button folds, SB folds, BB folds, UTG calls, UTG+1 calls.

Flop: (9.50 SB) 8[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
UTG checks, UTG+1 checks, <font color="#CC3333">Hero bets</font>, CO calls, UTG calls, UTG+1 calls.

Turn: (6.75 BB) 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
UTG checks, UTG+1 checks, <font color="#CC3333">Hero ???</font>

I still have an overpair, but with a 4 card straight on the board i'm not sure if i win often enough at showdown for it to be worth a bet to protect my hand here.